A5021426023- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Cold Atom Physics and Bose-Einstein Condensates
- Astrophysics and Cosmic Phenomena
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Stellar, planetary, and galactic studies
- Black Holes and Theoretical Physics
- Quantum Chromodynamics and Particle Interactions
- Relativity and Gravitational Theory
- Advanced Thermodynamics and Statistical Mechanics
- History and Developments in Astronomy
- Superconducting and THz Device Technology
- Quantum Mechanics and Applications
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Neutrino Physics Research
- Experimental and Theoretical Physics Studies
- Biofield Effects and Biophysics
- Quantum Electrodynamics and Casimir Effect
University of Florida
2016-2025
Florida Department of State
2023
Lawrence Berkeley National Laboratory
2016
European Organization for Nuclear Research
1980-2015
Naval Postgraduate School
2010
Institute for Advanced Study
2006
University of California, Santa Barbara
1992-2003
Isaac Newton Institute for Mathematical Sciences
1995
University of Cambridge
1995
Harvard University
1994
Experiments are proposed which address the question of existence "invisible" axion for whole allowed range decay constant. These experiments exploit coupling to electromagnetic field, emission by sum, and/or cosmological abundance and presumed clustering axions in halo our galaxy.
Axion models have a spontaneously broken $Z(N)$ symmetry. The resulting discretely degenerate vacua and domain-wall solitons are incompatible with the standard cosmology. It is possible, however, to introduce small breaking interaction into axion without upsetting Peccei-Quinn mechanism. In that case domain walls disappear certain time after their formation in early universe. Their presence for limited period might lead galaxy formation.
Axions in the micro eV mass range are a plausible cold dark matter candidate and may be detected by their conversion into microwave photons resonant cavity immersed static magnetic field. The first result from such an axion search using superconducting first-stage amplifier (SQUID) is reported. SQUID amplifier, replacing conventional GaAs field-effect transistor successfully reached axion-photon coupling sensitivity band set present models sets stage for definitive utilizing near...
This Letter reports the results from a haloscope search for dark matter axions with masses between 2.66 and 2.81 μeV. The excludes range of axion-photon couplings predicted by plausible models invisible axion. unprecedented sensitivity is achieved operating large-volume at subkelvin temperatures, thereby reducing thermal noise as well excess ultralow-noise superconducting quantum interference device amplifier used signal power readout. Ongoing searches will provide nearly definitive tests...
We show that cold dark matter axions thermalize and form a Bose-Einstein condensate (BEC). obtain the axion state in homogeneous isotropic universe, derive equations governing small perturbations. Because they BEC, differ from ordinary nonlinear regime of structure formation upon entering horizon. Axion BEC provides mechanism for production net overall rotation halos, alignment cosmic microwave anisotropy multipoles.
This Letter reports on a cavity haloscope search for dark matter axions in the Galactic halo mass range 2.81-3.31 μeV. utilizes combination of low-noise Josephson parametric amplifier and large-cavity to achieve unprecedented sensitivity across this range. excludes full axion-photon coupling values predicted benchmark models invisible axion that solve strong CP problem quantum chromodynamics.
The Gauss-Codazzi formalism is used to obtain exact solutions Einstein's equations in the presence of domain walls. Domain walls are shown have repulsive gravitational fields. most general solution for a planar wall obtained. Also, motion spherical an asymptotically flat space-time derived.
Experiments are described to search for axions floating about in the halo of our galaxy and emitted by sun. Expressions given signal strengths these experiments.Received 13 May 1985DOI:https://doi.org/10.1103/PhysRevD.32.2988©1985 American Physical Society
Originally hypothesized to explain the absence of $C\phantom{\rule{0}{0ex}}P$ violation in strong interactions, axion has emerged as a candidate constituent dark matter. This review guides reader through search methods for QCD well new kinds particles with axionlike properties. For each case, physics method, signatures, and background are discussed depth. A must-have addition quiver hunters.
The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO look for axions or axion-like particles (ALPs) originating in the Sun via Primakoff conversion of solar plasma photons. In terms signal-to-noise ratio, about 4–5 orders magnitude more sensitive than CAST, currently most powerful helioscope, reaching sensitivity to axion-photon couplings down few × 10−12 GeV−1 and thus probing large fraction unexplored ALP parameter space....
We show that dark matter axions cause an oscillating electric current to flow along magnetic field lines. The induced in a strong ${\stackrel{\ensuremath{\rightarrow}}{B}}_{0}$ produces small ${\stackrel{\ensuremath{\rightarrow}}{B}}_{a}$. propose amplify and detect ${\stackrel{\ensuremath{\rightarrow}}{B}}_{a}$ using cooled $LC$ circuit very sensitive magnetometer. This appears be suitable approach searching for axion the $1{0}^{\ensuremath{-}7}$ $1{0}^{\ensuremath{-}9}\text{ }\mathrm{eV}$...
A search experiment has been carried out to look for relic cosmic axions trapped in the halo of our Galaxy and limits on their coupling ${g}_{a\ensuremath{\gamma}\ensuremath{\gamma}}$ galactic abundance are presented axion mass range ${m}_{a}=(5.4\ensuremath{-}5.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ eV. The detector consisted a tunable high-$Q$ microwave cavity immersed liquid helium permeated by strong magnetic field. low-noise receiver with cryogenic HEMT amplifier as...
The exceptional group ${E}_{7}$ is proposed as a spontaneously broken gauge underlying unified field theory of the strong, electromagnetic, and weak interactions. resulting model, which has only one coupling constant multiplet elementary fermions, shown to be compatible with phenomenology electromagnetic interactions, including ${e}^{+}{e}^{\ensuremath{-}}$ annihilation high-energy neutrino scattering.
Recent determinations of cosmological parameters point to a flat Universe, whose total energy density is composed about two-thirds vacuum and one-third matter. Ordinary baryonic matter relegated small fraction the latter, within which luminous part an order magnitude smaller yet. Particle dark matter, i.e., one or more relic particle species from big bang, thus strongly suggested as dominant component in Universe. The axion, hypothetical elementary pseudoscalar arising Peccei-Quinn solution...
If axions exist, they contribute significantly to the present energy density. These have been collisionless and nonrelativistic since their appearance at \ensuremath{\sim} 1 GeV. Hence axion density perturbations survive on essentially all scales, once are dominant, grow in turn create amplify baryon fluctuations. Axions can cluster into galactic halos even though mass \ensuremath{\lesssim}${10}^{\ensuremath{-}2}$ eV. halo matter is mainly axions, Peccei-Quinn order parameter...
We have built and operated a large-scale axion detector, based on method originally proposed by Sikivie, to search for halo axions. The apparatus consists of cylindrical tunable high-Q microwave cavity threaded axially static high magnetic field. This field stimulates axions that enter the convert into single photons. conversion is resonantly enhanced when resonant frequency near rest mass energy. experiment cooled 1.5 K electromagnetic power spectrum emitted measured an ultra-low-noise...
The axion is a hypothetical elementary particle and cold dark matter candidate. In this rf cavity experiment, halo axions entering resonant immersed in static magnetic field convert into microwave photons, with the resulting photons detected by low-noise receiver. ADMX Collaboration presents new limits on axion-to-photon coupling local mass density from search range $1.9--2.3\ensuremath{\mu}\mathrm{eV},$ broadening to $1.9--3.3\ensuremath{\mu}\mathrm{eV}.$ addition, we report first results...